+1 on treating clothing with permethrin. I buy pretreated but have sent some existing items to InsectShield. As far as carrying an antibiotic, it's actually a good idea as a means of preventing post-bite infection. There are a few studies that have been around for a while that have shown that a single 200 mg dose of doxycycline taken after a tick bite is very effective in preventing Lyme disease. I spoke with my doctor a few years ago and he wrote a prescription for 200 mg which I keep in my first aid kit. I get a new RX with each annual physical so I have always have a fresh dose. I haven't had to use it, though. The treated clothing has done a good job in keeping ticks off.
My approach is to avoid ticks to prevent bites by using permethrin treated clothing as a first line of defense and carry the doxycycline as my second line of infection prevention in case I discover an attached tick.
A reference for the doxy study is Nadelman RB, et al. Prophylaxis with single-dose doxycycline for the preventionof Lyme disease after an ixodes scapularis tick bite. New England Journal of Medicine. 2001: 345(2);79-84.